Welf. & Inst. Code, § 655

(a) When any person has applied to the probation officer, pursuant to Section 653, to request commencement of juvenile court proceedings to declare a minor a ward of the court under Section 602 and the probation officer does not cause the affidavit to be taken to the prosecuting attorney pursuant to Section 653 within 21 court days after such application, the applicant may, within 10 court days after receiving notice of the probation officer’s decision not to file a petition, apply to the prosecuting attorney to review the decision of the probation officer, and the prosecuting attorney may either affirm the decision of the probation officer or commence juvenile court proceedings.

(b) When any person has applied to the probation officer or the district attorney, pursuant to Section 653, to commence juvenile court proceedings to declare a minor a dependent child of the court or a ward of the court under Section 601 and the probation officer or district attorney fails to file a petition within 21 court days after making such application, the applicant may, within 10 court days after receiving notice of the probation officer’s or district attorney’s decision not to file a petition, apply to the juvenile court to review the decision of the probation officer or district attorney, and the court may either affirm the decision of the probation officer or district attorney or order him or her to commence juvenile court proceedings.

(c) Nothing in subdivision (b) shall be construed so as to allow district attorneys to file a petition to make a minor a ward of the court under Section 601, except as specifically allowed by Section 653 in accordance with subdivision (e) of Section 601.3.